Evaluation of the integrity and function of the CNS in critically ill patients with ischemic, metabolic or traumatic brain insults is ordinarily assessed by episodic neurologic exams and cannot be done in an ongoing fashion. An inexpensive method for early diagnosis and detailed neurophysiological assessment in patients with dementia (Alzheimers, Parkinsonian) is also problemental at this time. The purpose of this project is to develop and test a computer-based system for acquisition, analysis, and display of scalp-recorded neuroelectric signals (electro- encephalogram and evoked potentials). This tool can be used to investigate the degree of dysfunction in neurologically impaired patients, to correlate the indices developed with other measures of cerebral function, and to evaluate the effectiveness of various therapeutic interventions.